Last updated 11:02 a.m. ET
(CBS/AP) -- Violent evening storms following a day of triple-digit temperatures wiped out power to more than 2 million customers across the eastern United States and caused at least five fatalities - including a 90-year-old Virginia woman asleep in bed when a tree slammed into her home, and two young cousins on a camping trip in southern New Jersey.
Widespread power outages were reported from Indiana to New Jersey, with the bulk of the service interruptions concentrated on Washington, D.C. and surrounding areas, leaving many without power - and without air conditioning - on a day that temperatures are expected to reach triple digits across the eastern U.S.
Earlier Friday, the nation's capital reached 104 degrees topping a record of 101 set in 1934.
Authorities say the violent storms have left at least five people dead.
Anne Arundel County, Md., police said in a news release Saturday that 25-year-old Kevin Obrien was killed when a tree fell onto his car late Friday. Two other people in the car suffered minor injuries.
In Pittsgrove, N.J., police say two boys, ages 2 and 7, were killed after a tree fell on their tent during the storm early Saturday at Parvin State Park. Authorities say the boys' families had been camping at adjacent sites when the storm hit, and the families decided to huddle together in one tent. They say the heavy winds and rains from the storm snapped a pine tree, which then fell on the families' tent.
The boys suffered serious injuries and died.
A line of thunderstorms, 100 miles from tip-to-toe, rolled through the Washington. D.C. area Friday night packing winds of 50-to-80 mph, reports Topper Shutt of CBS D.C. affiliate WUSA-TV. The same clump of storms hit southeastern Ohio and West Virginia with hurricane force winds Friday evening.
These types of storms, known as Mesoscale Convective System, or Derecho, are usually seen in the Midwest and not in the Mid-Atlantic, Shutt adds.
Storm damage, including uprooted trees, also delayed the start of third-round play at the AT&T National golf tournament in Bethesda, Md. Spectators and volunteers are being barred from the course Saturday owing to safety concerns.
More than 20 elderly residents at an apartment home in Indianapolis were displaced when the facility lost power due to a downed tree. Most were bused to a Red Cross facility to spend the night, and others who depend on oxygen assistance were given other accommodations, the fire department said.
The storms toppled three tractor trailers on Interstate 75 near Findlay, Ohio. Fallen trees were blamed on both deaths in Springfield, Va. the 90-year-old woman in her home and a man driving a car, Fairfax County police spokeswoman Mary Ann Jennings said.
In addition, a park police officer was injured by an uprooted tree in the northern Virginia county, and an 18-year-old man was struck by a power line, Jennings said. He was in stable condition after receiving CPR, she said.
"Our officers and firefighters are out there with power saws, trying to clear the streets," Jennings said.
West Virginia Gov. Earl Ray Tomblin declared a state of emergency after more than 500,000 customers in 27 counties were left without electricity.
At least four utility poles fell on a road in Columbus, Ohio, making it too dangerous for people in four cars to get out, police said. One person was taken to a hospital.
As of 1 a.m. Saturday, Pepco was reporting 406,000 outages in the District of Columbia and Montgomery and Prince George's counties, Md.
Amtrak suspended its service from Washington, D.C., to Philadelphia due to the storms, at least until mid-morning.
"We have more than half our system down," said Pepco spokeswoman Myra Oppel. "This is definitely going to be a multi-day outage."
In the Washington, D.C., area, the Metrorail subway trains were returned to their endpoints due to the storms and related damage, officials said.
"It has had a widespread effect on the region," Metro spokesman Dan Stessel said early Saturday. He said about 17 train stations were operating on backup power due to local power outages, but that he didn't anticipate service being disrupted on Saturday.